Steel target question

[AZRedhawk44]

I'm definitely noticing that shooting steel with 9mm is less... authoritative... than many other calibers.

When a target just needs an audible "clang!" to count, no problem.  But when you have to knock it down, it seems that it takes a shot + a dose of the shooter's willpower and belief in fairies (clap your hands!) to make certain the target falls over.

The .38super spacepimp-raceguns go POPPOPPOP! most enthusiastically, with the little jets of smoke and fire coming out of their compensators and such, and seem to never have any problems knocking over the little steel popper targets. 

The .45acp singlestack guys definitely seem to have the inertia game in their favor when it comes to knocking active targets down.  You never see a steel popper target hit with a .45 fail to go down.

And even the .40 guys seem to do well enough.

I see guys running 8-shot S&W N-frames and I assume they are running light .357's in moonclips in those rigs, but they don't seem to be having any problems with target-smacking.

I'm running 124gr LRN cast boolits I got from Mastercast, behind 4.0gr Titegroup.

Which tactic would give me greater steel target knock-down-effectiveness?

1.  Changing to a slower burning but higher velocity powder?  Perhaps AA #7.  Accurate's data show they can get a 147gr LRN moving just shy of 1000fps with #7.
2.  Fussing with the existing load, moving into +p territory or possibly even into "9mm major" territory with the 120-ish grain weight loads?
3.  Split the difference and look for a 135-ish grain bullet offering from a vendor.
4.  Switch to a jacketed/plated bullet and try for more velocity from the 115-125grain territory.


I'm assuming that inertia/momentum is the dominant factor in slapping down a 25+ pound steel target, rather than kinetic energy.  Mass * Velocity has more bearing... than Mass * Velocity^2.  Making mass (and therefore diameter) a much more critical component of success than in modern hollowpoint defensive ammo.  Right?

(No I don't want to start a 9/45 fight here... eventually I will switch back to .45acp once I have my chops down at this game.  9mm is much cheaper to learn the ropes with, however.)

[French G.]

I always had great success with steel and my 9mm unless you count triple tapping a forward falling popper. For the record that doesn't exactly make it fall faster. My unscientific observation is that a bullet or pieces thereof that ricochets must still have energy to make it fly. I watch cast bullets sometimes get a good bit of altitude. JHP, fragments everywhere. I was shooting Berry's plated and it seemed like the thin "jacket" combined with the dead soft lead inside made a bullet that hit steel and smushed flat, usually fall within a few feet of the plate.  My observation was that it hit steel much better than WWB out of the same gun. I was on Berry's 115, WSP, 4.4gr Titegroup and getting about 1170.

Funny thing with that load, I had been using 4.3gr and bumped it up. I had been chronoed once and they were going 1130, and the 5 they ran were pretty close. So I get to a big match, offer up my chrono bullets and tell the guy, based on an extrapolated guess, that they ought to be about 1165. He pulled the trigger, 1165, gave me back the rest of the chrono bullets he was supposed to fire. 

[Hawkmoon]

Energy is energy, and it doesn't matter if you pump it up by increasing the mass or the velocity -- or both. FWIW, most of the 9mm competitors at my range shoot out-of-the-box Winchester USA 115-grain FMJ.

Of course, the steel plates at our range were noted for being discriminatory. I shot one one night with Win USA 230-grain .45 Auto and watched -- WATCHED, verified by the timer --- five rounds splatter the paint on one plate and it didn't go down. The next guy shot it with a 9mm and down it went.

Since it sounds like you're loading your own, I'd go with a 147-grainer and get as much velocity out of it as you safely can.

[Jim147]

I've seen guys running 4.3 and up for Tightgroup with lead before.

Watch your oal and watch for pressure. It can spike quick with that fast of a powder.

jim

[charby]

I have no problem dropping steel with .38 special, lead 147g at 700fps. (well when I can hit it)

I shoot steel with a standard revolver.

[CNYCacher]

Are these the kind of steel targets that stand up and you knock them over backward?  Maybe you are hitting them low and doing too much push and not enough tip?

I don't know anything, just throwing that out there.

[AZRedhawk44]

Energy is energy, and it doesn't matter if you pump it up by increasing the mass or the velocity -- or both.

I have no problem dropping steel with .38 special, lead 147g at 700fps.

147gr @ 700fps is only about 150 ft/lbs of energy.  It's a power factor (weight * velocity / 1000) of 103.

124gr @ 1050 is about 290 ft/lbs of energy.  It's a power factor of 130.

Sounds like no matter how I slice it, these steel targets are a bit more discriminatory than the ones you guys have experience with.  That .38special mousefart load above has the same energy as a .22LR (36gr @ 1300fps = 124ft/lb), but I bet it doesn't have the juice to bowl over the poppers at my range.  .22's cannot accomplish it.  They don't allow .380's or 9x18's to even compete.  9x19 is the minimum requirement.

I've been reading up on this, and it seems some people have a theory that hitting steel slower, with more mass, is more effective at knocking it over since it increases the contact time against the plate during bullet deformation, and the inertia transfer against it. 

I'd love to know if a .223 could knock over one of these poppers, but there's a strict "no rifle rounds allowed against steel" rule.

I still have about 1500-2000 of these 124gr bullets so I'm going to play with increasing velocity for the next few months and see if that helps.  Once I use these up, I'm going to go to a heavier 135-147gr bullet.

One other thing I've wondered about is my bullets have a strongly tapered nose/ogive and a pointy-rounded tip... I bet a flatter meplat would transfer more inertia against the plate and result in more mushrooming against the steel (and more inertia transfer to make it fall more reliably). 

[Fly320s]

What sort of steel plates are you shooting?  The common "pepper poppers" used in USPSA and IDPA? Plate racks? LaRue resetting targets?  You may know that the poppers need to be calibrated (set up) to fall from a 9mm hit in the center of the round part of the steel.  If the targets are properly set, they will fall when you hit them with a minor 9mm load. So, you should load ammo to achieve a blend of accuracy, recoil impulse, and cost.

It looks to me like most of the real competitors are shooting 147 grain 9mm at velocities that just make minor PF. From what I've heard, that gives a smooth, flat recoil impulse which helps get the gun back on target quickly.  Center punch the popper and you don't have to watch/wait/wish for the plate to fall. Hit it and move on.

If you are shooting a match where you need to get the target to the ground quickly, like some man-on-man competitions, then just drive the target to the ground with multiple hits.  For USPSA and IDPA, I think you would be better off by shooting minor PF loads and going for center hits.

[AZRedhawk44]

Yep, pepper poppers.

[HankB]

Physics trivia:

Energy doesn't knock plates (or anything else) down - momentum does.

[AJ Dual]

Physics trivia:

Energy doesn't knock plates (or anything else) down - momentum does.

Yep, learned the same thing the hard way in a three-gun bowling pin shoot. Even .40 does not knock them over as well as .45, and even the lowly .22 LR which fails to penetrate all the way through the pins, and thus transfers 100% of it's momentum, will often knock them over better than .223fmj which sails right through them.

Best of both worlds is .44 Magnum. lots of momentum transfer due to the wide fat slug, but also blows fist-sized chunks out of the bowling pins due to all it's energy.

[Nick1911]

Physics trivia:

Energy doesn't knock plates (or anything else) down - momentum does.

I'd argue it's energy transfer that's the important part.  You can have a heavy slug (lots of momentum), but if it doesn't effectively transfer that energy, it won't knock down a target.

[Hawkmoon]

I've been reading up on this, and it seems some people have a theory that hitting steel slower, with more mass, is more effective at knocking it over since it increases the contact time against the plate during bullet deformation, and the inertia transfer against it. 

Not only that, I was just at the range and kind of slunk around the periphery of a discussion that led to an informal consensus that lead or plated lead bullets do better on steel plates than FMJ, and that JHP do better than FMJ of the same weight, because the softer bullets "smoosh" ( to use a technical term) against the plates and expend more of their energy in contact, whereas a FMJ may not expend as much energy in deformation before the plate moves enough to allow the bullet to bounce off.

That might explain my experience of actually watching my shots hit the plates almost dead center -- and the plates just sat there and laughed at me. I was shooting .45 Auto, Winchester USA 230-grain FMJ.

[French G.]

My plated 9mm load would launch a bowling pin, I attribute that to the bullet staying it the pin.

[birdman]

It's all in shot placement, my AR knocks PP's down just as well as my 45, 9, and my 5.7.

Now, you want to see a fun experiment, last trip we put a cantaloupe BEHIND 6 yellow-pages, and in front of a PP and hit it with my lapua...phone book exit wound was 4" across, melon was annihilated, and PP went down...of course, 5000 ft-lbs will do that

But regarding previous posts, it is momentum, not energy, especially since they are all inelastic collisions, so the higher momentum rounds (eg a 230gr 45acp) will be less sensitive to shot placement than a high energy/low momentum round (eg a 125gr +P+ 9mm which has the same energy, but 20-30% less momentum).

[Hawkmoon]

This may help: http://terra.gg.utah.edu/guns/energy.pdf

[peteinct]

AZredhawk, I shoot man on man plate matches at my club. All we have to do is knock down a plate at 1o-20 yards. It is all about hits that's it. To win you have to shoot quickly and less recoil can help. 9s aren't at a great disadvantage. You may give up a marginal hit.

To shoot bowling pins a 9 isn't preferred because it can't knock the pin from the table just knock it over. If youre using a rifle it can punch right through the pins. When we rifle shoot pins it is just knocking them down and the 9mm carbine guys always win.

Ive competed for several years now and the deciding element is the shooter not the equipment. Sure we would all like to have guns perfect for the game but practice will tell. In the plate game it is all about mental toughness and focus. Thats why I have problems. I choke at the end. A super duper blasto matic isn't going to fix that.

pete

[charby]

What sort of steel plates are you shooting?  The common "pepper poppers" used in USPSA and IDPA? Plate racks? LaRue resetting targets?  You may know that the poppers need to be calibrated (set up) to fall from a 9mm hit in the center of the round part of the steel.  If the targets are properly set, they will fall when you hit them with a minor 9mm load. So, you should load ammo to achieve a blend of accuracy, recoil impulse, and cost.

I think that is the problem. Where I shoot steel a .22lr knocks about half the plates over.

[zxcvbob]

Magnus bullets makes a 135 grain LRN bullet that works great in 9mm.  I load them with more Bullseye than I care to mention to shoot in an Argentina-made BHP.  The bullet number is either 505 or 515 (I can't remember which, I buy both of those bullets) and they are available from Midsouth Shooters Supply.